Adwords over-reporting conversion rates?

[dbriggs]

My Google AdWords program reports conversion rates that are double what my Yahoo store is reporting for the same time period. Anyone have a similar problem?

[Robsp]

Does your store get traffic from other sources?

[Houndstooth]

I have found this to be a problem. Google has admitted to us that their tracker may be double-counting(or more) conversions, depending on how the store is set up and where the conversion takes place. I'm not an expert at it though, I just know it's an issue.

[dbriggs]

Robsp:
Yes, our store gets traffic from other sources. However, we use the affiliate code program at Yahoo to keep track of who is coming in and from where. In regard to Google Adwords, the URL link I give them for our ads includes a unique affiliate code---which lets Yahoo tell us exactly how many people come in from a Google ad (not Google search) and how many of those visitors make a purchase.

It's interesting that Yahoo and Google AdWords report pretty much the same numbers for traffic (click-thrus). But when it comes to conversions, Google consistently reports numbers that are double what Yahoo is telling us.

I've contacted Google AdWords, and they asked me to send them more info so they could "check into it."

[Robsp]

It could be a timing issue. Google reports on everyone that bought after clicking in the last 30 days. Maybe Yahoo only measures users that buy on the same day as the click (then 50% is quite realistic). We see many products that have a delay between click and purchase.

[dbriggs]

Hmmm...that's interesting.
However, to rule out the possible timing problem, I went back and compared data from the month of October. Again, Google AdWords reports exactly double (and I mean really close to being exact double) the conversion rates that my Yahoo store is reporting. I would think that looking at data from two months ago would resolve any timing issues.
Hmmm...(again).

[Robsp]

To investigate I would find out how the store measures conversions and secondly make a number of snapshots of the sales on Adwords on a daily basis. When "late" conversions come in you should see the past numbers rises over time.

We sell a lot of shareware with a 2 week trial and often see the reported sales at the end of the month at least double because of this effect.

[Robsp]

To add one point; looking at longer intervals is not going to make a difference when the store only measures "same visit orders". On the contrary the longer you measure the bigger the difference gets as Adwords continues to collect conversions.

Then again I do not know how and where you guys measure in the process so this is just some educated guessing....

[AdWordsAdvisor]

As I've mentioned a time or two in the past, I am not a leading authority on the nuances of conversion tracking. But, on the other hand, I am fortunate to know some folks who are. ;)

So, I asked one of them to take a look at this thread, and see if he could offer any insight - and have what I hope will be some useful info.

He replied:

...we may report duplicate transactions if for any reason people are refreshing or reloading the conversion page.

...most likely, if it's almost exactly double, then the page is either prompting users to refresh/reload, or the site has a print button that is not properly designed and does a page refresh when printing.

Hope this'll give you a place to start looking, dbriggs. And welcome to WebmasterWorld!

AWA

[dbriggs]

Thanks everyone for sharing what you know...this is great forum.
I suppose it's possible that my visitors could be reloading the conversion page (thanks AWA for asking about this), but it doesn't seem that this would account for doubling the numbers.

I suppose this conversation might be better suited to a forum about Yahoo stores, as it seems this is where I need to do some more investigation. But for those of you who are interested, here's how I use the Yahoo store affiliate program to measure both traffic and conversions from my Google ads.

Yahoo store has a fairly typical affiliate system--I create unique codes to give to my affiliates to place in their website links to me. When visitors come to me via those links, Yahoo store reports traffic from that unique code and also lets me know how many of these visitors place an order and how much they spend. I assume Yahoo gets this info by simply tracking the code to the confirmation page, which indicates a purchase has been made (all products in my store are downloadable--the credit card transaction is complete at time of purchase).

So I created an affiliate code that I give to Google for the URL in my ads. When visitors come in from my Google ads, Yahoo reports the traffic, number of orders, and total sales attributed to that code. Yahoo's affiliate code reporting appears to be updated daily. I can look at stats over an entire year or just look at what came in from my Google Adwords yesterday. I guess I don't have any reason to believe the Yahoo numbers are skewed, it seems to be a pretty straight-forward affiliate code tracking process.

As most of you know, the Google AdWords program generates its conversion reports from a piece of Google AdWords javascript that you put on a conversion page on your website--in my case, the Yahoo store confirmation page. How Yahoo inserts this javascript exactly, I'm not entirely sure. All I've been instructed to do (by Google) is insert the Google javascript in a form box that Yahoo store calls the "order confirmation message."

It seems to work, but like I've said, the conversions that Google AdWords reports to me are always about double the conversions that Yahoo store shows from the same ad. I'm hoping to hear from Google soon with more details about what might be causing the problem.